1. Field of the Invention
The present invention relates to a rectifier assembly for an air-cooled generator, a heat sink structure for use in such a rectifier assembly, and a method of producing a heat sink structure for a rectifier assembly.
2. Discussion of the Related Art
It is known that excessive heat accumulation can cause the rectifier of an automotive generator to malfunction. Efforts therefore have been directed to cooling such rectifiers. In some cases, the cooling is provided by air, while in other cases, the cooling is provided by significantly more expensive and complicated liquid cooling techniques (e.g., using a water coolant). The prior art techniques for cooling the rectifier of a generator typically provide inadequate cooling (e.g., the heat is not dissipated as fast as it is accumulated, especially in the case of air-cooled arrangements), are difficult to assemble, take too much time to assemble, require complex structures or expensive parts, leave the diodes of the rectifier susceptible to bridging as a result of salt or other forms of contamination, and/or fail to provide sufficiently robust isolation between the electrically positive and negative parts of the rectifier.
There is consequently a need in the art for a rectifier assembly for an air-cooled generator, a heat sink structure for use in such a rectifier assembly, and/or a method of producing a heat sink structure for a rectifier assembly, each of which provide(s) sufficient cooling of the rectifier diodes to prevent damage or malfunctioning of the rectifier diodes, is easy to assemble in a relatively short period of time, requires few, if any, complex structures or expensive parts, avoids bridging as a result of salt or other forms of contamination, and/or provides robust isolation between the electrically positive and negative parts of the rectifier.
It is a primary object of the present invention to overcome the foregoing problems and/or to satisfy at least one of the aforementioned needs by providing a rectifier assembly for an air-cooled generator, a heat sink structure for use in such a rectifier assembly, and/or a method of manufacturing a heat sink structure for a rectifier assembly, wherein the heat sink structure includes a substantially annular base plate with cooling fins projecting therefrom and/or wherein the heat sink structure is arranged so that air is permitted to flow around at least a majority of radially inner edges of the heat sink structure and also around at least a majority of radially outer edges of the heat sink structure, thereby facilitating transfer of heat from the heat sink structure to the air.
To achieve this and other objects and advantages, the present invention provides a heat sink structure for a rectifier assembly of an air-cooled generator. The heat sink structure comprises a substantially annular base having an inner edge and an outer edge. At least one of the inner edge and outer edge has a cooling fin arrangement projecting out from the base. The heat sink structure also is provided with diode mounts. Each of the diode mounts is adapted to retain a respective diode in a thermally conductive manner. Heat from each respective diode is transferred to the base and to the cooling fin arrangement, to provide a heat sink effect.
The present invention also provides a method of manufacturing a heat sink structure for a rectifier assembly. The method comprises the steps of configuring a sheet of thermally conductive material to include a substantially annular base and radial extensions of the base, and bending the radial extensions so that the radial extensions are substantially perpendicular to the annular base, thereby defining perpendicular extensions.
A rectifier assembly for an air-cooled generator is also provided by the present invention. The rectifier assembly comprises a substantially annular support, a substantially annular heat sink, and a substantially annular insulator. The substantially annular support is thermally and electrically conductive. It is adapted to hold negative-side diodes in such a way that 1) a ground terminal of each negative-side diode is electrically connected to the support, 2) a phase terminal of each negative-side diode remains electrically connectable to a respective one of several stator output phases from the generator, and 3) the negative-side diodes are thermally connected to the support so that heat from the negative-side diodes is transferred to the support, to provide a heat sink effect. The substantially annular heat sink structure is thermally and electrically conductive. The heat sink structure is adapted to hold positive-side diodes in such a way that 1) a positive terminal of each positive-side diode is electrically connected to the heat sink structure, 2) a phase terminal of each positive-side diode remains connectable to a respective phase output from a respective one of the stator output phases from the generator, and 3) the positive-side diodes are thermally connected to the heat sink structure so that heat from the positive-side diodes is transferred to the heat sink structure, to provide a heat sink effect. The substantially annular electrical insulator is sandwiched between the support and the heat sink structure to electrically insulate the support from the heat sink structure. The support has a spacer feature that permits air to flow around at least a majority of radially inner edges of the support and the heat sink structure and also around at least a majority of radially outer edges of the support and the heat sink structure. This, in turn, facilitates the transfer of heat from the heat sink structure and the support to the air.
The expression xe2x80x9csubstantially annularxe2x80x9d, as used in this disclosure, encompasses not only purely annular structures (i.e., O-shaped structures), but also C-shaped structures and other structures that approximate a purely annular shape.
Still other objects, advantages, and features of the present invention will become more readily apparent when reference is made to the accompanying drawing and the associated description contained herein.